The present invention relates generally to improvements in plant growth accelerating apparatus and particularly to such apparatus including structure for tilting the axis of the plant bed during turning thereof, improved gravity watering systems for turning plant beds, and improved rooting media for use in such apparatus as well as methods of making such rooting media.
This application is an improvement upon the apparatus disclosed and claimed in the applicant's copending application for U.S. Letters Patent, Ser. No. 428,995 filed Dec. 27, 1973 for ROTARY PLANT GROWTH ACCELERATING APPARATUS, and the disclosure of that prior application is incorporated herein by reference.
The apparatus disclosed in Ser. No. 428,995 is highly effective in increasing plant yields by removing the growing plants from the constraints of gravity. However, it has been found that not only is the rate of formation of carbohydrates by photosynthesis increased by gravity nullification, but the respiration rate is likewise increased when the plants are in the dark or in low intensity light conditions.
Although this effect can be nullified in turn by providing supplemental lighting so that the plants are constantly subjected to light, certain plants will not develop normally under such conditions, those plants requiring alternate periods of light and dark (photoperiodic requirement), examples thereof being strawberries, onions, pansies and poinsettias; other plants such as tomatoes will grow better if subjected to alternating periods of light and dark. In fact the increased rate of respiration in the dark may be so great and the relationship between the light and dark periods such that the fixed carbon accumulation by plants during photosynthesis is completely consumed during respiration by the dark.
Problems have also been encountered in maintaining and manufacturing certain of the rotary seals utilized in apparatus of this type heretofore and improved rooting media also are considered highly desirable.
Reference is also made to the article by R. R. Dedolph et al. entitled "Casual Basis of Gravity Stimulus Nullification by Clinostat Rotation", Plant Physiology, Vol. 42, No. 10, Oct. 1967, pp. 1373-1383.